Computer-aided Design and Computer-aided Manufacturing Fabricated Polyoxymethylene used for Maxillary Removable Partial Denture Framework

Abstract

The increasing need for a dental substitution of partially edentulous has resulted in the development of removable partial denture (RPD) material and fabrication technique. Polyoxymethylene (POM) or acetal resin is one of an interesting alternative material for RPDs due to superior esthetics, high strength, elasticity and lightweight. Furthermore, POM is available to design and fabricate using computer-aided design and computer-aided manufacturing (CAD-CAM) systems that are used for RPDs fabrication due to more simple procedure and more accurate fit compare to the conventional. The aim of this case report was to describe the treatment for upper partially dentate patient who had no desirable of metal-color and heavyweight denture. POM was chosen as a RPD framework material and combined CAD-CAM system in design and fabrication. 3D model was scanned from master cast owing to higher precise technique for capturing the physiologic extension in tissue-borne RPDs. The framework component was similar to conventional RPDs. Nonetheless, differences are the thickness of all components must be 2.0 mm for adequate strength of denture and except for direct retainers that should be thicker (1.5 mm) and engage deeper undercut (0.5 mm) than metal clasp. Air abrasion on POM which is low surface energy material, must be done to increase surface area on account of being main adhesion between framework and polymethylmethacrylate of mechanical retention. The combination of CAD-CAM technique and POM block in fabrication of maxillary RPD framework resulted in accurate fit of denture; more lightweight and more pleasurable wear as a non-metal denture. After 1 year of use, denture revealed well-condition and proper function. Using POM for RPD framework in this article showed patient satisfaction on the appearance with no metal display and also lighter weight of denture. The fabrication technique was a convenient method and created precisely fitting of denture framework led to reduction of insertion time